This invention relates to a combined punch and binding machine, and more particularly, to an improved pressure bar assembly for use in punching.
Combined punch and binding machines are known in the art as shown in U.S. Pat. Nos. 3,122,761; 3,125,887; 3,227,023; and 3,793,660. In such machines paper or text material and covers are punched along one edge with apertures and then bound using plastic binding elements having a backbone and curled fingers of the type disclosed in U.S. Pat. No. 1,970,285, so as to form a book, chart or the like. The punching mechanism may be either manually or electrically operated, while the binding operation is normally manual. The punching mechanism includes a laterally extending row of punches mounted on the machine, which are selectively advanced to a punching position and retracted from that position. The pressure bar assembly carries set pins which engage and actuate the punches and stripper fingers which cooperate in retracting the punches. The same pressure bar assembly is used in both the manually- and electrically-operated machines.
In the prior machines, the pressure bar is a fabricated assembly having numerous parts and elements, each of which is stamped or machined and then assembled to form the pressure bar. The separate fabrication and assembling of such parts requires close tolerance machining and stamping and precise alignment in assembly, which can result in a relatively high cost of production.
It is an object of this invention to reduce the close tolerance machining and stamping requirements for the pressure bar.
It is another object of this invention to enhance the ease of assembly and manufacture and reduce the cost of production.
This and other objects of this invention will become apparent from the following description and appended claims.